In a computer memory system, it is very important that the user be able to retrieve an exact copy of the data stored in the devices that constitute the system. To facilitate the retrieval of an exact copy, error control information may be added to each data word prior to storage in the data storage devices. As each data word is retrieved, the portion of each word that contains the error control information is examined so that errors present in the portion of the data word that contains the information can be detected and corrected. However, an error control code suitable for use with memory systems that include one type of storage device may not be suitable for use with systems that include other types of storage devices.